学习EXT第四天--开始使用Grid

概述: 本教程将以XML为数据源，带你进入Grid的世界。

本文涉及的范例代码，可以在这里下载。一个完成好的例子可在这里找到。

步骤一 定义数据(Data Definition)

首先要让Grid知道XML文档定义了每一行是什么数据。正如所见，我们命名了"item"在下面的XML样本中。

XML样本数据 文件名：sheldon.xml


<?xml version="1.0" encoding="UTF-8"?>


<ItemSearchResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2006-06-28">


<OperationRequest>


<HTTPHeaders>


<Header Name="UserAgent"


Value="Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Avant Browser; Avant Browser; .NET CLR 1.0.3705; .NET CLR 2.0.50727; .NET CLR 1.1.4322; Media Center PC 4.0; InfoPath.2)"></Header>


</HTTPHeaders>


<RequestId>18CZWZFXKSV8F601AGMF</RequestId>


<Arguments>


<Argument Name="Service" Value="AWSECommerceService"></Argument>


<Argument Name="AssociateTag" Value="ws"></Argument>


<Argument Name="SearchIndex" Value="Books"></Argument>


<Argument Name="Author" Value="Sidney Sheldon"></Argument>


<Argument Name="SubscriptionId" Value="1A7XKHR5BYD0WPJVQEG2"></Argument>


<Argument Name="Version" Value="2006-06-28"></Argument>


<Argument Name="Operation" Value="ItemSearch"></Argument>


</Arguments>


<RequestProcessingTime>1.05041599273682</RequestProcessingTime>


</OperationRequest>


<Items>


<Request>


<IsValid>True</IsValid>


<ItemSearchRequest>


<Author>Sidney Sheldon</Author>


<SearchIndex>Books</SearchIndex>


</ItemSearchRequest>


</Request>


<TotalResults>203</TotalResults>


<TotalPages>21</TotalPages>


<Item>


<ASIN>0446355453</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446355453%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446355453%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>Master of the Game</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446613657</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446613657%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446613657%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>Are You Afraid of the Dark?</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446357421</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446357421%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446357421%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>If Tomorrow Comes</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446607207</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446607207%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446607207%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Vision</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>Tell Me Your Dreams</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446357448</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446357448%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446357448%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>Bloodline</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446532673</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446532673%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446532673%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>The Other Side of Me</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446356573</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446356573%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446356573%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>A Stranger in the Mirror</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0060198346</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0060198346%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0060198346%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>William Morrow & Company</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>The Sky Is Falling</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446354732</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446354732%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446354732%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>Nothing Lasts Forever</Title>


</ItemAttributes>


</Item>


<Item>


<ASIN>0446341916</ASIN>


<DetailPageURL>

http://www.amazon.com/gp/redirect.html%3FASIN=0446341916%26tag=ws%26lcode=xm2%26cID=2025%26ccmID=165953%26location=/o/ASIN/0446341916%253FSubscriptionId=1A7XKHR5BYD0WPJVQEG2

</DetailPageURL>


<ItemAttributes>


<Author>Sidney Sheldon</Author>


<Manufacturer>Warner Books</Manufacturer>


<ProductGroup>Book</ProductGroup>


<Title>The Naked Face</Title>


</ItemAttributes>


</Item>


</Items>


</ItemSearchResponse>

接着需要定义某一列为“统一标识（Unique Identifier）”,即ID,根据“id"所设置的那个节点来读取值（样本代码第九行）。本例中的样本数据是”ASIN"列。

数据定义的最后部分就是指定你需要显示的字段(Fields),把这些字段放到一个数组之中，并保证这些字段与你的XML数据中元素名称是一致的，而且还要注意先后顺序，这里的顺序不需要和XML文件中顺序一致。

var dataStore = new Ext.data.Store({
proxy : new Ext.data.HttpProxy({url: 'XML/sheldon.xml'}),
reader : new Ext.data.XmlReader(
{record : 'Item',id : 'ASIN'},
['Author','Manufacturer','ProductGroup','Title']
)
});

步骤二 列模型（Column Model）

下一步便是定义Column Model 列模型。简单地说，就是通过一些属性的设置，决定每一列怎么控制或怎么显示，这是一个由每列的配置参数组成的数组。注意，出现的顺序应该与刚才定义“字段”的数组一致。较常见的参数通常是header和width，所以你会觉得这两项是必须要设置的，然而宽度（width）其实不总是需要的，因为稍后我们将使用autoWidth/Height来代替。

列模型样本

var colModel = new Ext.grid.ColumnModel([
{header : "Author",width:120,dataIndex:'Author'},
{header : "Manufacturer",width:180,dataIndex:'Manufacturer'},
{header : "ProductGroup",width:115,dataIndex:'ProductGroup'},
{header : "Title",width:100,dataIndex:'Title'}
]);

最后是将DataStore和Column Model两样东西传入到Grid，渲染结果，然后加载来自DataStore的数据，这些就是你让Grid工作起来的所有因素！

进行渲染！

var grid = new Ext.grid.GridPanel({
el : 'GridXml',
ds : dataStore,
cm : colModel,
height:350,
width:600
});

grid.render();
dataStore.load();

在body部分加入：

<div id="GridXml"></div>